Domain Wall Control of Topological Qubits in the Kitaev SSH Chain

TL;DR

This paper demonstrates how introducing domain walls in an SSH Kitaev chain can precisely control topological zero modes, enabling robust, local manipulation of Majorana-based qubits for quantum computing.

Contribution

It introduces a novel method of using domain walls to control topological qubits, offering a more robust and simpler alternative to tuning global parameters.

Findings

Domain walls flip zero mode parity, enabling on/off control of Majoranas.

Anisotropic superconductivity enhances defect control over boundary modes.

The approach allows local addressing of topological qubits via domain walls.

Abstract

Zero energy states in one dimensional SSH Kitaev hybrid systems have emerged as promising candidates for topological qubits. In our work, we show that introducing a domain wall into a chain with anisotropic superconducting correlations provides a powerful way to control both the number and the nature of these boundary modes. The defect acts as a digital knob: its presence or absence flips the parity of zero modes and thus decides whether an isolated Majorana exists at the chain ends. This on/off mechanism is significantly more robust and simpler than fine-tuning global parameters such as chemical potential or hopping amplitudes. Moreover, anisotropy provides an additional lever to calibrate the effect of the defect, opening a pathway to architectures where topological qubits can be locally addressed by domain walls. This proposal reframes defects not as imperfections, but as useful resources for quantum information and computation.